While installing homebridge in a second location I found that contrary to the installation instructions it is necessary to change the username in config.json Unless you do this, the Home app will find the username used for the previous location and think it is already paired to it.
Also, for those who don't want to install node and npm, you can just grab an installation disk image from https://nodejs.org/en/download/ It includes everything you need. One note, the installation path is under /usr/local/bin instead of /opt/local/bin